<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style type="text/css">
		.item{
			width: 50px;height: 50px;background-color: red;text-align: center;color: white;line-height: 50px;font-size:20px;position: absolute;left: 0px;top: 0px;border-radius: 50%;
		}
		body{margin: 0;position: relative;}
	</style>
</head>
<body>
	div.item{$}*100
</body>
<script type="text/javascript">
var divS=document.getElementsByClassName("item");
document.onmousemove = function(ev){
	var x = ev.clientX;
	var y = ev.clientY;
	divS[divS.length - 1].style.top = y + "px";
	divS[divS.length - 1].style.left = x + "px";
	document.body.insertBefore(divS[divS.length - 1], divS[0]);
}
</script>
</html>